It is known to provide electric hobs, for example, with “touch switches” having touch sensors. These trigger an operating function when a finger is placed on a specific labeled point on the hob plate. The operating principle is based on, for example, detecting capacitance, such that capacitive coupling may be detected between the finger placed on the hob plate and a corresponding touch sensor under the hob plate, which is connected to a drive and evaluation circuit.
Furthermore, German Patent DE 10361341A discloses an operating device which does not even require touching with the finger, but may instead even detect when a finger approaches a specific touch point. However, the problem here frequently arises that an operator does not recognize precisely at which point or in what way the finger has to be positioned for the desired operation.